Application should dictate choice IMHO:
1) Competition shooting/Hunting + handloading? 260 has most performance and brass options and supply. RP, FED, Nosler/Norma, now Lapua, re-formed 308, HSM, Corbon, etc. are some options for brass.
2) Competition/Hunting (realizing ltd. bullet choices - some match/target design) + affordable factory ammo only? Creedmoor. For handloaders, brass supply has been sketchy (likely Hornady prefers selling ammo anyway). Not many are 'forming brass' from any other case, and Hornady is the ONLY mfg. of brass/ammo to date, to my knowledge.
Since the Above 2 TYPICALLY see better speeds w/139-142s at common pressures they have that niche for many. (I know there are exceptions - but again, taking averages of the masses of users).
3) Competition + handloader + shooting 123-130s, OR Hunting + Handloading and using in a sporter length bbl where more powder is not utilized as much (say 19-23" bbl), I would choose 6.5x47 Lapua.
Bottom line, they ALL are CLOSER in performance than what most shooters can realize in differences. Brass supply, cost, die cost, ammo cost, and availability of all are more different than any difference on a Chronograph. That said, the very more critical 1,000 Yd shooters and beyond, claim the 260 w/139-142s are superior and unmatched by the 47 fwiw, but again, it's ALL ABOUT APPLICATION and above 3 scenario's is how I would decide.
Just my .02.
